Mercury rectifier



March i8, 1930. x.. T. ROBINSON 1,751,423

MERCURY REGTIFIER Filed Nov. 50. 1925 Hs Attorney.

Patented Mar. 1.8, 1930 UNITED STATES PATENT OFFICE LEWIS T. ROBINSON, OF SCHENECTADY, NEW YORK, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION 0F NEW YORK MERCURY RECTIFIER Application med November 30, 1925. Serial No. 72,234.

My invention relates to vapor electric devices wherein an anode and a mercury cathode are located' within and insulated from a container, and has for its principal object the provision of an improved arrangement for maintaining the vapor in the vicinity of the anode at pressure insuring efficient and res liable operation of the device.

It has been found that a vapor electric device such as a mercury rectifier will operate satisfactorily only when the vapor pressure in the vicinity of the anode is maintained within predetermined limits. If the anode temperature is too high, surface particles of the anode metal are vaporized and the resulting` metal vapor both decreases the effectiveness of the insulation between the anode and its support and increases the vapor pressure in the vicinity of the anode to avalue at which destructive arcs, commonly designated by the expression arc back, are likely to be produced. This difculty is also likely to be encountered when the anode temperature is too low for the rcason that mercury condensed on the cool areas of the anode surface flows down or drops on the hot areas of this surface and is vaporized, thereby producing localareas of high vapor pressure at the active surface of the anode.

The vapor pressure in the vicinity of the anodes maybe controlled to some extentbycirculating a cooling medium in contact with the outer wall of the tank or container. In order to maintain a. comparatively low vapor pressure at the top of the container where the electrodes are located, it is desirable that the cooling medium be circulated first in contact with the upper portion of the container wall and thereafter in contact with the lower portion of the container wall adjacent the cathode which is required to be cooled only to a temperature low enough to prevent deterioration of the insulation interposed between the main wall portion and the insulated wall portion upon which the cathode is supported. This method of temperature control, however, does not permit the accurate temperature control of the vapor adjacent the active surface of the anode necessary for the best operation of the device. In accordance with my invention, the method of temperature control just described is supplemented by individual temperature control either of the anode or of both the cathode and anode.

My invention will `be better understood from the following description when considered in connection with the accompanying drawings and its scope will be pointed out in the appended claims.

Referring to the drawings, Fig. 1 is a sectional view of a mercury rectifier wherein my invention has been embodied, and Figs. 2, 3 and 4 show various details in t-he anode cooling system of the rectifier.

Fig. 1 shows a rectifier comprising a mercury cathode 1 insulated from a container 2 and connected to a lead 3 through an insulated wall portion 4 of the container. The container 2 and the insulated wall portion 4 are surrounded bycooling chambers 5 and 6 respectively through which a cooling medium is circulated 'by means of pipes 7 to 10, this cooling medium preferably being introduced to the chamber 5 through pipe 7 and removed therefrom through pipe 8. Fluid for cooling the top of the container 2 is supplied through the pipe 7 and an annular opening 11 Surrounding the upper edge of the tank and is re'- ilroved therefrom through a discharge pipe leads 14 are supported by and insulated from the cover of the container 2. Each of the anodes 13 is surrounded by a baffle 15 which is supported by the top of the container 2 and is provided with an opening 1G facing the inner wall of the container. The details of the baffle construction are shown in Figs. 2, 3 and 4.

It will be observed that the upper portion of the bafiie is surrounded by a chamber 17 to which a cooling medium is supplied through a pipe 18 and from which it is discharged through a pipe 19 and that staggered longitudinal strips20 are mounted within the chamber 17 to insure that thecooling medium is circulated from the top to the bottom of the baffle. The arrangement of the strips 20 is clearly shown by Fig. 3. As indicated by Fi 4, fiuid is supplied to the bafiie cooling'chamers 17 through pipe 21 and is discharged therefrom through a pipe 22.

With this structure, the temperature in the A plurality of anodes 13 connected to vicinity of the anode may be regulated in a means for causing said medium to be moved to manner to maintain the vapor pressure in the interior of the anode chamber at a value Which is below that at which arc back is likely to occur. At this temperature, the greater portion of the mercury vapor is condensed near the lower opening of the baiie, a low pressure is maintained within the anode chamber, and the tendency to arc back is greatly reduced.

It will be readily understood that independent cooling of the anode may be effected with other constructions than that shown and described.

The embodiment of the invention illustrated and described herein has been selected for the purpose of clearly setting forth the principles involved. It will be apparent however that the invention is susceptible of being modifiedto meet the different conditions encountered' in its use and I therefore aim to cover by the appended claims all modifications within the true spirit and scope of my invention. A

What Ilclaim as new and desire to secure by Letters Patent of the United States, isf- 1. The method of controlling the temperature of a device comprising an anode and a mercury cathode located in a container having'an insulated wall portion for supporting said cathode which comprises circulating a cooling medium in contact with the outer wall of said container from the top to the bottom thereof, circulating said medium in contact with the insulated wall portion upon which said cathode is supported and cooling 'the space surrounding said anode to a temperature at which the vapor pressure therein is maintained at a value below that at which arcback is likely to occur.

2. The method of controlling the temperature of a device comprising an anode and a mercury cathode located in a container having an insulated wall portion for supporting said cathode which comprises circulating a cooling medium in contact with the wall of said container Jfrom the top to the bottom thereof, cooling the insulated wall portion upon which said cathodeis supported to a temperature at which injury to the insulation between said wall portions is prevented, and cooling the space surrounding said anode to maintain the vapor pressure therein at a value below that at which arc back is likely to occur.

3. A vapor electric device wherein a mercury cathode and an anode are mounted within' a container and insulated therefrom comprising a baille surrounding said anode, and means for circulating a cooling medium in contact with the surface of said baiiie.

4:. A vapor electric device wherein a mercury cathode and Aan anode are mounted within a container and insulated therefrom, comprising a wall surrounding said anode,

means for circulating a cooling medium in contact with the surface of said Wall, and

and ro between the ends of said wall.

In witness whereof, I have hereunto set my hand this 28th day of November, 1925.

LEWIS T. ROBINSON.

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